Node and method for downlink scheduling and hybrid automatic repeat request timing

ABSTRACT

Example embodiments presented herein are directed towards a base station, and corresponding method therein, for determining a control timing configuration. The control timing configuration provides a subframe timing for configuring PUSCH and uplink HARQ-ACK control timing for a cell serving a user equipment in a multiple cell communications network. The user equipment is served by a TDD based cell and a FDD based cell. Example embodiments are also directed towards a user equipment, and corresponding method therein, determining the control timing configuration discussed above.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. National Stage patentapplication Ser. No. 14/239,470, filed Feb. 18, 2014, entitled “NODE ANDMETHOD FOR DOWNLINK SCHEDULING AND HYBRID AUTOMATIC REPEAT REQUESTTIMING,” which claims priority to International Application Serial No.PCT/SE2013/051208, International filing date Oct. 16, 2013, which claimsthe benefit of U.S. Provisional Application Ser. No. 61/869,086, filedAug. 23, 2013, the entirety of each of which is incorporated herein byreference.

TECHNICAL FIELD

Example embodiments presented herein are directed towards a base stationand user equipment, and corresponding methods therein, for determining aone control timing configuration. The control timing configurationprovides a subframe timing setting for configuring Physical UplinkShared Channel (PUSCH) and uplink Hybrid Automatic RetransmissionRequest Acknowledgment (HARQ-ACK) control timing for a cell serving theuser equipment in a multiple cell communications network. The userequipment is served by a Time Division Duplex (TDD) based cell and aFrequency Division Duplex (FDD) based cell.

BACKGROUND Long Term Evolution Systems

Long Term Evolution (LTE) uses Orthogonal Frequency DivisionMultiplexing (OFDM) in the downlink direction and a Discrete FourierTransform (DFT)-spread OFDM in the uplink direction. The basic LTEdownlink physical resource can thus be seen as a time-frequency grid,where each resource element corresponds to one OFDM subcarrier duringone OFDM symbol interval. In the time domain, LTE downlink transmissionsmay be organized into radio frames of 10 ms, with each radio frameconsisting of ten equally-sized subframes of length Tsubframe=1 ms.

Furthermore, the resource allocation in LTE is typically described interms of resource blocks, where a resource block corresponds to oneslot, e.g., 0.5 ms, in the time domain and 12 subcarriers in thefrequency domain. A pair of two adjacent resource blocks in timedirection, e.g., 1.0 ms, is known as a resource block pair. Resourceblocks are numbered in the frequency domain, starting with 0 from oneend of the system bandwidth.

The notion of virtual resource blocks (VRB) and physical resource blocks(PRB) has been introduced in LTE. The actual resource allocation to auser equipment is made in terms of VRB pairs. There are two types ofresource allocations, localized and distributed. In the localizedresource allocation, a VRB pair is directly mapped to a PRB pair, hencetwo consecutive and localized VRBs are also placed as consecutive PRBsin the frequency domain. On the other hand, the distributed VRBs are notmapped to consecutive PRBs in the frequency domain, thereby providingfrequency diversity for data channel transmitted using these distributedVRBs.

Downlink transmissions are dynamically scheduled, i.e., in each subframethe base station transmits control information regarding which terminalsdata is transmitted and upon which resource blocks the data istransmitted, in the current downlink subframe. This control signaling istypically transmitted in the first 1, 2, 3 or 4 OFDM symbols in eachsubframe and the number n=1, 2, 3 or 4 is known as the Control FormatIndicator (CFI). The downlink subframe also contains common referencesymbols, which are known to the receiver and used for coherentdemodulation of, e.g., the control information.

From LTE Release 11 and onwards, the above described resourceassignments may also be scheduled on the enhanced Physical DownlinkControl Channel (EPDCCH). For 3GPP Release 8 to 3GPP Release 10, onlyPhysical Downlink Control Channel (PDCCH) is available.

PDCCH Search Space

LTE defines so-called search spaces, which describe the set of CCEs theterminal is supposed to monitor for scheduling assignments/grantsrelating to a certain component carrier. A search space is a set ofcandidate control channels formed by CCEs on a given aggregation level,which the terminal is supposed to attempt to decode. As there aremultiple aggregation levels, corresponding to one, two, four, and eightCCEs, a terminal has multiple search spaces. In each subframe, theterminals will attempt to decode all the PDCCHs that can be formed fromthe CCEs in each of its search spaces. If the CRC checks, the content ofthe control channel is declared as valid for this terminal and theterminal processes the information (scheduling assignment, schedulinggrants, etc.). Each terminal in the system therefore has aterminal-specific search space at each aggregation level.

In several situations, there is a need to address a group of, or all,terminals in the system. To allow all terminals to be addressed at thesame time, LTE has defined common search spaces in addition to theterminal-specific search spaces. A common search space is, as the nameimplies, common, and all terminals in the cell monitor the CCEs in thecommon search spaces for control information. Although the motivationfor the common search space is primarily transmission of various systemmessages, it may be used to schedule individual terminals as well. Thus,it may be used to resolve situations where scheduling of one terminal isblocked due to lack of available resources in the terminal-specificsearch space. More important, the common search space is not dependentof user equipment configuration status. Therefore, the common searchspace may be used when the NW needs communicate with the user equipmentduring user equipment reconfiguration periods.

PUCCH

If the mobile terminal has not been assigned an uplink resource for datatransmission, the L1/L2 control information, e.g., channel-statusreports, Hybrid-ARQ acknowledgments, and scheduling requests, istransmitted in uplink resources, e.g., resource blocks, specificallyassigned for uplink L1/L2 control on 3GPP Release 8 PUCCH. Theseresources are located at the edges of the total available cellbandwidth. Each such resource consists of 12 “subcarriers”, e.g., oneresource block, within each of the two slots of an uplink subframe. Inorder to provide frequency diversity, these frequency resources arefrequency hopping on the slot boundary, i.e., one “resource” consists of12 subcarriers at the upper part of the spectrum within the first slotof a subframe and an equally sized resource at the lower part of thespectrum during the second slot of the subframe or vice versa. If moreresources are needed for the uplink L1/L2 control signaling, e.g., incase of very large overall transmission bandwidth supporting a largenumber of users, additional resources blocks can be assigned next to thepreviously assigned resource blocks.

Carrier Aggregation

The LTE Release 10 standard has recently been standardized, supportingbandwidths larger than 20 MHz. One important requirement on LTE Release10 is to assure backward compatibility with LTE Release 8. This shouldalso include spectrum compatibility. That would imply that an LTERelease 10 carrier, wider than 20 MHz, should appear as a number of LTEcarriers to an LTE Release 8 terminal. Each such carrier may be referredto as a Component Carrier (CC). In particular for early LTE Release 10deployments it may be expected that there will be a smaller number ofLTE Release 10 capable terminals compared to many LTE legacy terminals.Therefore, it is necessary to assure an efficient use of a wide carrieralso for legacy terminals, i.e., that it is possible to implementcarriers where legacy terminals may be scheduled in all parts of thewideband LTE Release 10 carrier. The straightforward way to obtain thiswould be by means of Carrier Aggregation (CA). CA implies that an LTERelease 10 terminal may receive multiple CC, where the CC have, or atleast the possibility to have, the same structure as a Release 8carrier.

The number of aggregated CC as well as the bandwidth of the individualCC may be different for uplink and downlink. A symmetric configurationrefers to the case where the number of CCs in downlink and uplink is thesame whereas an asymmetric configuration refers to the case that thenumber of CCs is different. It is important to note that the number ofCCs configured in a cell may be different from the number of CCs seen bya terminal: A terminal may for example support more downlink CCs thanuplink CCs, even though the cell is configured with the same number ofuplink and downlink CCs.

During initial access a LTE Release 10 terminal behaves similar to a LTERelease 8 terminal. Upon successful connection to the network a terminalmay, depending on its own capabilities and the network, be configuredwith additional CCs in the UL and DL. Configuration is based on RRC. Dueto the heavy signaling and rather slow speed of RRC signaling, it isenvisioned that a terminal may be configured with multiple CCs eventhough not all of them are currently used. If a terminal is configuredon multiple CCs this would imply it has to monitor all DL CCs for PDCCHand PDSCH. This implies a wider receiver bandwidth, higher samplingrates, etc., resulting in high power consumption.

To mitigate the above problems, LTE Release 10 supports activation ofCCs on top of configuration. The terminal monitors only configured andactivated CCs for PDCCH and PDSCH. Since activation is based on MediumAccess Control (MAC) control elements, which are faster than RRCsignaling, activation/de-activation may follow the number of CCs thatare required to fulfill the current data rate needs. Upon arrival oflarge data amounts multiple CCs are activated, used for datatransmission, and de-activated if not needed anymore. All but one CC,the DL Primary CC (DL PCC), may be de-activated. Activation providestherefore the possibility to configure multiple CC but only activatethem on a need basis. Most of the time a terminal would have one or veryfew CCs activated resulting in a lower reception bandwidth and thusbattery consumption.

Scheduling of a CC is done on the PDCCH via downlink assignments.Control information on the PDCCH is formatted as a Downlink ControlInformation (DCI) message. In Release 8 a terminal only operates withone DL and one UL CC, the association between DL assignment, UL grantsand the corresponding DL and UL CCs is therefore clear. In LTE Release10 two modes of CA needs to be distinguished. The first case is verysimilar to the operation of multiple Release 8 terminals, a DLassignment or UL grant contained in a DCI message transmitted on a CC iseither valid for the DL CC itself or for associated (either viacell-specific or UE specific linking) UL CC. A second mode of operationaugments a DCI message with the Carrier Indicator Field (CIF). A DCIcontaining a DL assignment with CIF is valid for that DL CC indictedwith CIF and a DCI containing an UL grant with CIF is valid for theindicated UL CC.

DCI messages for downlink assignments contain among others resourceblock assignment, modulation and coding scheme related parameters, HARQredundancy version, etc. In addition to those parameters that relate tothe actual downlink transmission most DCI formats for downlinkassignments also contain a bit field for Transmit Power Control (TPC)commands. These TPC commands are used to control the uplink powercontrol behavior of the corresponding PUCCH that is used to transmit theHARQ feedback.

In LTE Release 10, the transmission of PUCCH is mapped onto one specificuplink CC, the UL Primary CC (UL PCC). Terminals only configured with asingle DL CC, which is then the DL PCC, and UL CC, which is then the ULPCC, are operating dynamic ACK/NACK on PUCCH according to 3GPP Release8. The first Control Channel Element (CCE) used to transmit PDCCH forthe DL assignment determines the dynamic ACK/NACK resource on 3GPPRelease 8 PUCCH. Since only one DL CC is cell-specifically linked withthe UL PCC no PUCCH collisions may occur since all PDCCH are transmittedusing different first CCE.

Upon reception of DL assignments on a single Secondary CC (SCC) orreception of multiple DL assignments, a PUCCH format (which is referredto as CA PUCCH herein) that can carry the HARQ-ACK of multiple servingcells should be used. A DL SCC assignment alone is untypical. The eNBscheduler should strive to schedule a single DL CC assignment on the DLPCC and try to de-activate SCCs if not needed. A possible scenario thatmay occur is that eNB schedules terminal on multiple DL CCs includingthe PCC. If the terminal misses all but the DL PCC assignment it willuse Release 8 PUCCH instead of CA PUCCH. To detect this error case eNBhas to monitor both the Release 8 PUCCH and the CA PUCCH.

In LTE Release 10, the CA PUCCH format is based on the number ofconfigured CC. Configuration of CC is based on RRC signaling. Aftersuccessful reception/application of the new configuration a confirmationmessage is sent back making RRC signaling very safe.

CA PUCCH Transmission Scheme

In this application, CA PUCCH refers to means of transmitting HARQ-ACKof multiple serving cells in the UL. For Rel-10 LTE, CA PUCCH can beembodied in one of the following two approaches. The first method isbased on the use of PUCCH format 3 that is based on DFTS-OFDM. Themultiple ACK/NACK bits are encoded to form 48 coded bits. The coded bitsare then scrambled with cell-specific (and possibly DFTS-OFDM symboldependent) sequences. 24 bits are transmitted within the first slot andthe other 24 bits are transmitted within the second slot. The 24 bitsper slot are converted into 12 QPSK symbols, DFT precoded, spread acrossfive DFTS-OFDM symbols and transmitted within one resource blocks(bandwidth) and five DFTS-OFDM symbols (time). The spreading sequence isuser equipment specific and enables multiplexing of up to five userswithin the same resource blocks. For the reference signals cyclicshifted CAZAC sequences, e.g., computer optimized sequences, may beused.

The second CA PUCCH method is called channel selection. The basicprinciple is that the user equipment is assigned a set of PUCCH format1a/1b resources. The user equipment then selects one of resourcesaccording to the ACK/NACK sequence the user equipment should transmit.On one of the assigned resources, the user equipment would then transmita QPSK or BPSK. The eNB detects which resource the user equipment usedand which QPSK or BPSK value the user equipment fed back on the usedresource and combines this into a HARQ response for associated DL cells.A similar type of mapping including a bundling approach is also done forTDD as in the FDD, in case the user equipment is configured with channelselection.

Time Division Duplex

Transmission and reception from a node, e.g., a terminal or userequipment 501 and base station 401 in a cellular system such as LTE, maybe multiplexed in the frequency domain or in the time domain (orcombinations thereof). Frequency Division Duplex (FDD) as illustrated tothe left in FIG. 1 implies that downlink and uplink transmission takeplace in different, sufficiently separated, frequency bands. TimeDivision Duplex (TDD), as illustrated to the right in FIG. 1, impliesthat downlink and uplink transmission take place in different,non-overlapping time slots. Thus, TDD can operate in unpaired spectrum,whereas FDD requires paired spectrum.

Typically, the structure of the transmitted signal in a communicationsystem is organized in the form of a frame structure. For example, LTEuses ten equally-sized subframes of length 1 ms per radio frame asillustrated in FIG. 2.

In case of FDD operation, illustrated in the upper section of FIG. 2,there are two carrier frequencies, one for uplink transmission (fUL) andone for downlink transmission (fDL). At least with respect to theterminal in a cellular communication system, FDD may be either fullduplex or half duplex. In the full duplex case, a terminal may transmitand receive simultaneously, while in half-duplex operation, the terminalmay not transmit and receive simultaneously. The base station is capableof simultaneous reception/transmission though, e.g., receiving from oneterminal while simultaneously transmitting to another terminal. In LTE,a half-duplex terminal is monitoring/receiving in the downlink exceptwhen explicitly being instructed to transmit in a certain subframe.

In case of TDD operation, illustrated in the lower section of FIG. 2,there is only a single carrier frequency and uplink and downlinktransmissions are always separated in time also on a cell basis. As thesame carrier frequency is used for uplink and downlink transmission,both the base station and the mobile terminals need to switch fromtransmission to reception and vice versa. An essential aspect of any TDDsystem is to provide the possibility for a sufficiently large guard timewhere neither downlink nor uplink transmissions occur. This is requiredto avoid interference between uplink and downlink transmissions. ForLTE, this guard time is provided by special subframes, e.g., subframe 1and, in some cases, subframe 6, which are split into three parts: adownlink part (DwPTS), a guard period (GP), and an uplink part (UpPTS).The remaining subframes are either allocated to uplink or downlinktransmission.

TDD allows for different asymmetries in terms of the amount of resourcesallocated for uplink and downlink transmission, respectively, by meansof different downlink/uplink configurations. In LTE, there are sevendifferent configurations as shown in FIG. 3. It should be appreciatedthat a DL subframe may mean either DL or the special subframe.

To avoid severe interference between downlink and uplink transmissionsbetween different cells, neighbor cells should have the samedownlink/uplink configuration. If this is not done, uplink transmissionin one cell may interfere with downlink transmission in the neighboringcell and vice versa. Hence, the downlink/uplink asymmetry may typicallynot vary between cells, but is signaled as part of the systeminformation and remains fixed for a long period of time.

PUSCH Scheduling and PHICH Timings

The PUSCH scheduling timing and the corresponding HARQ feedback PHICHtiming are described extensively in 3GPP Technical Specification 36.213.A basic summary is provided below for discussing the example embodimentspresented herein.

For TDD UL/DL configurations 1-6 and normal HARQ operation, the userequipment shall upon detection of a PDCCH/ePDCCH with uplink DCI formatand/or a PHICH transmission in subframe n intended for the userequipment, adjust the corresponding PUSCH transmission in subframe n+k,with k given in Table 8-2 of TS 36.213 (reproduced in Table 1 below),according to the PDCCH/ePDCCH and PHICH information. For FDD, k=4.

TABLE 1 k for TDD configurations 0-6 TDD UL/DL subframe number nConfiguration 0 1 2 3 4 5 6 7 8 9 0 4 6 4 6 1 6 4 6 4 2 4 4 3 4 4 4 4 44 5 4 6 7 7 7 7 5

For TDD UL/DL configuration 1-6, if a user equipment is configured withone serving cell, or if the user equipment is configured with more thanone serving cell and the TDD UL/DL configuration of all the configuredserving cells is the same, an HARQ-ACK received on the PHICH assigned toa user equipment in subframe i is associated with the PUSCH transmissionin the subframe i-k as indicated by the following Table 8.3-1 of TS36.213 (reproduced below). For FDD, k=4.

TABLE 2 k for TDD configurations 0-6 TDD UL/DL subframe number iConfiguration 0 1 2 3 4 5 6 7 8 9 0 7 4 7 4 1 4 6 4 6 2 6 6 3 6 6 6 4 66 5 6 6 6 4 7 4 6

For TDD, if the user equipment is configured with one serving cell, orif the user equipment is configured with more than one serving cell andthe TDD UL/DL configuration of all the configured serving cells is thesame, for PUSCH transmissions scheduled from serving cell c in subframen, the user equipment shall determine the corresponding PHICH resourceof serving cell c in subframe n+k_(PHICH), where k_(PHICH) is given inTable 9.1.2-1 of TS 36.213 (reproduced in Table 3 below). For FDD,k_(PHICH)=4.

TABLE 3 k_(PHICH) for TDD TDD UL/DL subframe index n Configuration 0 1 23 4 5 6 7 8 9 0 4 7 6 4 7 6 1 4 6 4 6 2 6 6 3 6 6 6 4 6 6 5 6 6 4 6 6 47

Within the downlink control information (DCI) transmitted to the userequipment via PDCCH/ePDCCH for scheduling PUSCH, there is a transmitpower control (TPC) command. For a PUSCH transmission at subframe i, theTPC command from subframe i−K_(PUSCH) should be incorporated. For TDDUL/DL configurations 1-6, K_(PUSCH) is given in Table 5.1.1.1-1 of TS36.213 (reproduced in Table 4 below). For FDD, K_(PUSCH)=4.

TABLE 4 K_(PUSCH) for TDD TDD UL/DL subframe number i Configuration 0 12 3 4 5 6 7 8 9 0 — — 6 7 4 — — 6 7 4 1 — — 6 4 — — — 6 4 — 2 — — 4 — —— — 4 — — 3 — — 4 4 4 — — — — — 4 — — 4 4 — — — — — — 5 — — 4 — — — — —— — 6 — — 7 7 5 — — 7 7 —

SUMMARY

In current 3GPP standards, the possibility of a user equipment beingserved by an aggregated FDD and TDD carrier simultaneously is notdiscussed or addressed. Thus, at least one example object of the exampleembodiments presented herein is to provide mechanisms to implementcontrol timing configurations for establishing PUSCH and PhysicalHARQ-ACK control timing for a cell serving a user equipment in a FDD andTDD carrier aggregated network. The example embodiments presented hereinhave the example advantage of providing a simple scheme to derive thesubframes for the timing of HARQ and the scheduling for TDD and FDDaggregation.

Accordingly, some of the example embodiments are directed towards amethod, in a base station, for determining a control timingconfiguration. The control timing configuration provides a subframetiming setting for configuring PUSCH and uplink HARQ-ACK control timingfor a cell serving a user equipment in a multiple cell communicationsnetwork. The user equipment is served by a TDD based cell and a FDDbased cell. The method comprises determining a control timingconfiguration for a secondary cell. The secondary cell is one of the TDDbased cell or the FDD based cell. The determining is based on a type ofa scheduling cell. The type of the scheduling cell is one of the FDDbased cell or the TDD based cell. The method further comprisesimplementing the at least one control timing configuration for PUSCH anduplink HARQ-ACK control timing for a cell serving the user equipment.

Some of the example embodiments are directed towards a base station fordetermining a control timing configuration. The control timingconfiguration provides a subframe timing setting for configuring PUSCHand uplink HARQ-ACK control timing for a cell serving a user equipmentin a multiple cell communications network. The user equipment is servedby a TDD based cell and a FDD based cell. The base station comprisesprocessing circuitry configured to determine a control timingconfiguration for a secondary cell. The secondary cell being one of theTDD based cell or the FDD based cell. The processing circuitry isconfigured to determine the control timing configuration based on a typeof the scheduling cell. The type of the scheduling cell is one of theFDD based cell or the TDD based cell. The processing circuitry isfurther configured to implement the control timing configuration forPUSCH and uplink HARQ-ACK control timing for a cell serving the userequipment.

Some of the example embodiments are directed towards a method, in a userequipment, for determining a control timing configuration. The controltiming configuration provides a subframe timing setting for configuringPUSCH and uplink HARQ-ACK control timing for a cell serving the userequipment in a multiple cell communications network. The user equipmentis served by a TDD based cell and a FDD based cell. The method comprisesdetermining a control timing configuration for a secondary cell. Thesecondary cell is one of the TDD based cell or the FDD based cell. Thedetermining is based on a type of a scheduling cell. The type of thescheduling cell is one of the FDD based cell or the TDD based cell. Themethod further comprises implementing the control timing configurationfor PUSCH and uplink HARQ-ACK control timing for a cell serving the userequipment.

Some of the example embodiments are directed towards a user equipmentfor determining a control timing configuration. The control timingconfiguration provides a subframe timing setting for configuring PUSCHand uplink HARQ-ACK control timing for a cell serving the user equipmentin a multiple cell communications network. The user equipment is servedby a TDD based cell and a FDD based cell. The user equipment comprisesprocessing circuitry configured to determine a control timingconfiguration for a secondary cell. The secondary cell is one of the TDDbased cell or the FDD based cell. The processing circuitry is configuredto determine the control timing configuration based on a type of atleast one scheduling cell. The type of the scheduling cell being one ofthe FDD based cell or the TDD based cell. The processing circuitry isfurther configured to implement the at least one control timingconfiguration for PUSCH and uplink HARQ-ACK control timing for a cellserving the user equipment.

DEFINITIONS ACK Acknowledgement AL Aggregation Level

ARQ Automatic Repeat reQuest

BPSK Binary Phase Shift Keying C-RNTI Cell Radio Network TemporaryIdentifier CA Carrier Aggregation CAZAC Constant Amplitude ZeroAutocorrelation CC Component Carrier CCE Control-Channel Elements CFIControl Format Indicator CIF Carrier Indicator Field CRC CyclicRedundancy Check DCI Downlink Control Information DFT Discrete FourierTransform DFTS DFT Spread DL Downlink DTX Discontinuous TransmissionDwPTS Downlink Part of a Special Subframe

ePDCCH enhanced Physical Downlink Control Channel

E-UTRA Evolved Universal Terrestrial Radio Access GP Guard Period FDDFrequency Division Duplexing HARQ Hybrid Automatic Repeat Request LSBLeast Significant Bit LTE Long Term Evolution MAC Medium Access ControlNACK Non-Acknowledgement NW Network OFDM Orthogonal Frequency DivisionMultiplexing PCell Primary Cell PCC Primary CC PDCCH Physical DownlinkControl Channel PDSCH Physical Downlink Shared Channel PHICH PhysicalHybrid ARQ Indicator Channel PRB Physical Resource Blocks PUCCH PhysicalUplink Control Channel PUSCH Physical Uplink Shared Channel QPSKQuadrature Phase Shift Keying REG Resource Element Group RNTI RadioNetwork Temporary Identifier RRC Radio Resource Control SCell SecondaryCell SCC Secondary CC TDD Time Division Duplexing TPC Transmit PowerControl UE User Equipment UL Uplink UpPTS Uplink Part of a SpecialSubframe VRB Virtual Resource Blocks

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particulardescription of the example embodiments, as illustrated in theaccompanying drawings in which like reference characters refer to thesame parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe example embodiments.

FIG. 1 is an illustrative example of frequency and time division duplex;

FIG. 2 is an illustrative example of an uplink/downlink time/frequencystructure for LTE in the case of FDD and TDD;

FIG. 3 is an illustrative example of the different uplink/downlink TDDconfigurations;

FIGS. 4A and 4B illustrate an example of PUSCH scheduling and feedbacktiming for a configuration 1 and configuration 2 cell, respectively,without the use of cross carrier scheduling;

FIG. 5 illustrates an example of control timing scheduling for a FDDbased PCell and scheduling cell and a TDD based SCell and scheduledcell, wherein the TDD based scheduled cell follows a FDD control timingconfiguration, according to some of the example embodiments;

FIG. 6 illustrates an example control timing scheduling for a FDD basedPCell and scheduling cell and a TDD based SCell and scheduled cell,wherein the TDD based scheduled cell follows its own control timingconfiguration, according to some of the example embodiments;

FIGS. 7 and 8 illustrate example control timing scheduling for a TDDbased PCell and scheduling cell and a FDD based SCell and scheduledcell, wherein the FDD based scheduled cell follows the configurationtiming of the TDD based PCell, according to some of the exampleembodiments;

FIGS. 9 and 10 illustrate example control timing scheduling for a TDDbased PCell and scheduling cell and a FDD based SCell and scheduledcell, wherein the FDD based scheduled cell follows its own configurationtiming, according to some of the example embodiments;

FIG. 11 illustrates an example of subframe hierarchy, according to someof the example embodiments;

FIGS. 12 and 13 illustrate example control timing scheduling for a TDDbased PCell and scheduling cell and a FDD based SCell and scheduledcell, wherein the FDD based scheduled cell follows a configurationtiming of configuration 0 or 6 based on the subframe hierarchy of FIG.11, according to some of the example embodiments;

FIGS. 14 and 15 illustrate example control timing scheduling for a TDDbased PCell and scheduling cell and a FDD based SCell and scheduledcell, wherein the FDD based scheduled cell follows a configurationtiming according to revised tables, according to some of the exampleembodiments;

FIG. 16 is an illustrative example of an example base stationconfiguration, according to some of the example embodiments;

FIG. 17 is an illustrative example of a user equipment configuration,according to some of the example embodiments;

FIG. 18 is a flow diagram depicting example operations which may betaken by the base station of FIG. 16, according to some of the exampleembodiments; and

FIG. 19 is a flow diagram depicting example operations which may betaken by the user equipment of FIG. 17, according to some of the exampleembodiments.

DETAILED DESCRIPTION

In the following description, for purposes of explanation and notlimitation, specific details are set forth, such as particularcomponents, elements, techniques, etc. in order to provide a thoroughunderstanding of the example embodiments. However, the exampleembodiments may be practiced in other manners that depart from thesespecific details. In other instances, detailed descriptions ofwell-known methods and elements are omitted so as not to obscure thedescription of the example embodiments.

As part of the development of the example embodiments presented herein,a problem will first be identified and discussed.

Interband TDD Carrier Aggregation with Different UL-DL Configurations onDifferent Carries

In LTE Release 10, carrier aggregation of TDD cells is specified withthe restriction that the U/D configurations for all the aggregated cellsare identical. The need to allow more flexible carrier aggregation ofTDD cells is to be addressed in Release 11 of LTE.

The U/D configurations of neighboring cells need to be compatible toavoid severe interference problems. However, there are cases where theneighboring cells are operated by different operators or differentwireless systems. The LTE TDD cells adjacent to those neighboringsystems are hence required to adopt certain compatible U/Dconfigurations. As a result, an operator may have several TDD cellshaving different U/D configurations on different frequencies.

To solve the HARQ control and A/N feedback timings in carrieraggregation systems with cells of different UL-DL configurations,WO2013/025143 and 3GPP TS 36.211 V11.1.0 3rd Generation PartnershipProject; Technical Specification Group Radio Access Network; EvolvedUniversal Terrestrial Radio Access (E-UTRA); Physical channels andmodulation (Release 11), taught that a user equipment is configured withat least one of two timing configuration numbers. The first timingconfiguration number is a PDSCH HARQ control timing configuration numberfor determining PDSCH HARQ A/N timings across all aggregated cells. Thesecond timing configuration number is a PUSCH control timingconfiguration number for determining PUSCH scheduling and thecorresponding HARQ A/N timings on PHICH across all aggregated cells.

As an example to illustrate the mechanism discussed above, considerPUSCH A/N feedback timing for a user equipment configured with carrieraggregation but and self-scheduling with configuration 1 cell and aconfiguration 2 cell shown in FIG. 4A and FIG. 4B, respectively. Asshown in FIG. 4A, table 3 may be utilized to determine the UL HARQcontrol timing for a configuration 1 cell. Utilizing the n-kcalculation, it is determined that such HARQ A/N feedbacks for PUSCH istransmitted from subframes 2, 3, 7 and 8 to subframes 6, 9, 1 and 4,respectively. Similarly, for a configuration 2 cell, utilizing the n-kcalculation, FIG. 4B illustrates HARQ A/N feedbacks for PUSCH aretransmitted from subframes 2 and 7 to subframes 6 and 1, respectively.

For a user equipment configured with these two serving cells withcross-carrier scheduling, the UL feedback is changed for the scheduledcell in some UL/DL configurations to allow more UL subframes to bescheduled. Examples of such scheduling are provided in WO2013/025143 and3GPP TS 36.211 V11.1.0 3rd Generation Partnership Project; TechnicalSpecification Group Radio Access Network; Evolved Universal TerrestrialRadio Access (E-UTRA); Physical channels and modulation (Release 11).

Overview of the Example Embodiments

In current 3GPP standards, the possibility of a user equipment beingserved by an aggregated FDD and TDD carrier simultaneously is notdiscussed or addressed. Thus, at least one example object of the exampleembodiments presented herein is to provide mechanisms to provide uplinkscheduling and HARQ control timing for a FDD and TDD carrier aggregatednetwork.

Therefore, some of the example embodiments presented herein are directedtowards how to allocate the HARQ timing and scheduling timing for PUSCHtransmission, for example, UL HARQ. According to some of the exampleembodiments, depending on which if either FDD or a certain UL/DLconfiguration for TDD is used, an applicable reference configuration isselected for the HARQ timing. An advantage of the example embodiments isthe ability to provide a simple scheme to derive the subframes for thetiming of HARQ and scheduling for TDD and FDD aggregation.

The applicable scheduling and HARQ timing for a user equipmentperforming aggregation between a FDD carrier and a TDD carrier dependson which of the carriers the scheduling is performed from. In addition,what impacts the applicable timings are whether the user equipment isconfigured with cross-carrier scheduling or not. The example embodimentsare mostly described from the basis of only aggregation between twocarriers although it is assumed that the aggregation may also beextended to more than two carriers.

In this section, the example embodiments will be illustrated in moredetail by a number of examples. It should be noted that these examplesare not mutually exclusive. Components from one example embodiment maybe tacitly assumed to be present in another embodiment and a personskilled in the art may use any number of the example embodiments inother example embodiments.

The example embodiments will be presented as follows. First, exampleembodiments directed towards the FDD based cell functioning as thescheduling cell, as described under the heading “The FDD based cell asthe scheduling cell”. Examples of scheduling for a TDD based SCell and aFDD based PCell are provided under the subheadings “Scheduled SCellfollows FDD timing” and “Scheduled SCell follows TDD timing”.

Numerous example embodiments are directed towards the TDD based cellfunctioning as the scheduling cell as described under the heading “TheTDD based cell as the scheduling cell”. Examples of such scheduling forthe FDD based SCell and a TDD based PCell are provided under thesubheadings “Scheduled SCell follows TDD timing”, “Scheduled SCellfollows FDD timing”, “Scheduled SCell follows timing according tosubframe hierarchy”, “FDD SCell scheduling based on revised tables” and“Cases where the PHICH is transmitted on the scheduled FDD cell”.

Finally, example node configurations and example node operations areprovided under the subheadings “Example node configuration” and “Examplenode operations”, respectively. It should be appreciated that in theexample embodiments described herein, the scheduling cell may be thePCell or a different SCell. In the example embodiments described herein,it is SCell which is scheduled (i.e., the scheduled cell).

The FDD Based Cell as the Scheduling Cell

Scheduled SCell Follows FDD Timing

According to some of the example embodiments, the HARQ-ACK for a PUSCHon a scheduled SCell is transmitted from the serving cell that carriedthe scheduling PDCCH/ePDCCH. The PUSCH scheduling and PHICH timings of aTDD SCell shall follow those for the FDD scheduling cell. Subframeswhich map toward a DL subframe on the SCell are excluded from thetiming. Such example embodiments are illustrated in FIG. 5.

FIG. 5 illustrates a FDD based cell as the primary cell and thescheduling cell. The secondary cell, which is the scheduled cell, is aTDD based cell with a configuration of 1. As shown in FIG. 5, HARQ-ACKfor PUSCH is scheduled with a timing value of 4 for all subframes for aPUSCH. Thus, uplink subframes 7, 8, 2 and 3 of the TDD based cell arescheduled for HARQ-ACK to subframes 1, 2, 6 and 7, of the FDD basedcell, respectively. It should be appreciated that scheduled HARQ-ACKtimings that map to a downlink subframe on the secondary scheduled TDDbased cell are excluded from feedback.

Scheduled SCell Follows TDD Timing

According to some of the example embodiments, the HARQ-ACK for a PUSCHon the scheduled SCell is transmitted from the scheduled SCell. ThePUSCH scheduling and PHICH timings of a TDD SCell shall follow its owntimings as defined by its own UL/DL configuration. Such exampleembodiments are illustrated in FIG. 6.

FIG. 6 illustrates a FDD based cell as the primary and the schedulingcell and the secondary and scheduled cell as a TDD based cell with aconfiguration of 1. As illustrated, the scheduled cell follows HARQ-ACKtimings according to table 3. Utilizing the n+k calculation, PUSCH fromsubframes 7, 8, 2 and 3 are scheduled for HARQ-ACK in subframes 1, 4, 6and 9, respectively, in the TDD based cell.

The TDD Based Call as the Scheduling Cell

According to some of the example embodiments, the HARQ-ACK for a PUSCHon the scheduled SCell is transmitted from the serving cell that carriedthe scheduling PDCCH/ePDCCH.

Scheduled SCell Follows TDD Timing

According to some of the example embodiments, the PUSCH scheduling andPHICH timings of a FDD SCell shall follow those for the TDD schedulingcell. Such example embodiments are illustrated in FIG. 7 and FIG. 8.

FIG. 7 illustrates a FDD based SCell which is also the scheduled cell.FIG. 7 further illustrates a TDD based PCell with a configuration of 1which is also the scheduling cell. In FIG. 7, the solid lines indicatePUSCH scheduling timings and the dashed lines indicate PHICH timings.For the case of a TDD configuration 1 PCell and a FDD SCell, four SCellUL subframes are to be schedulable, specifically, subframes 2, 3, 7 and8. These subframes are scheduled according to table 3 via the n+kcalculation. Thus, as provided by table 3, HARQ-ACK timings forsubframes 2, 3, 7 and 8 of the FDD based SCell are scheduled tosubframes 6, 9, 1 and 4, respectively, of the TDD based PCell.

FIG. 8 illustrates a FDD based SCell which is also the scheduled cell.FIG. 8 further illustrates a TDD based PCell with a configuration of 2which is also the scheduling cell. In FIG. 8, the solid lines indicatePUSCH scheduling timings and the dashed lines indicate PHICH timings.For the case of a TDD configuration 2 PCell and a FDD SCell, two SCellUL subframes are schedulable, specifically, subframes 2 and 7. Thesesubframes are scheduled according to table 3 via the n+k calculation.Thus, as provided by table 3, HARQ-ACK timing for subframes 2 and 7 ofthe FDD based SCell are scheduled to subframes 8 and 3, respectively, ofthe TDD based PCell.

Scheduled SCell Follows FDD Timing

According to some of the example embodiments, the PUSCH scheduling andPHICH timings of a FDD SCell shall follow its own timings. Specifically,the FDD SCell shall be scheduled with a timing value of 4 for allsubframes for a PUSCH. It should be appreciated that FDD schedulingwhich maps to downlink subframes in the TDD based cell are excluded fromPUSCH timing.

FIG. 9 provides an illustrative example of such an embodiment. In FIG.9, the solid lines indicate PUSCH scheduling timings and the dashedlines indicate PHICH timings. As shown in FIG. 9, a TDD based PCell,which is functioning as the scheduling cell, with a configuration of 1is aggregated with a FDD based SCell, which is functioning as thescheduled cell. In such a configuration, two SCell UL subframes may bescheduled, specifically, subframes 0 and 5. Therefore, utilizing thetiming value of 4 for all subframes, the PHICH for subframes 0 and 5 ofthe FDD based SCell are scheduled to subframes 4 and 9 of the TDD basedPCell. It should be appreciated that utilizing this example embodiment,a HARQ-ACK scheduling of the FDD based cell subframe 3 is not possibleas the PHICH for subframe 3 would be scheduled to subframe 7 of the TDDbased cell, which is an UL cell.

FIG. 10 provides another illustrative example of PUSCH scheduling andPHICH timings in which a FDD SCell follows its own timing. In FIG. 10,the solid lines indicate PUSCH scheduling timings and the dashed linesindicate PHICH timings. As shown in FIG. 10, a TDD based PCell, which isfunctioning as the scheduling cell, with a configuration of 2 isaggregated with a FDD based SCell, which is functioning as the scheduledcell. In such a configuration, six SCell UL subframes may be scheduled,specifically, subframes 4, 5, 7, 9, 0 and 2. Therefore, utilizing thetiming value of 4 for all subframes, subframes 4, 5, 7, 9, 0 and 2 ofthe FDD based SCell are scheduled to subframes 8, 9, 1, 3, 4 and 6 ofthe TDD based PCell. It should be appreciated that utilizing thisexample embodiment, a HARQ-ACK scheduling of the FDD based cell subframe3 is not possible as subframe 3 would be scheduled to subframe 7 of theTDD based cell, which is an UL cell.

Scheduled SCell Follows Timing According to Subframe Hierarchy

According to some of the example embodiments, the choice of whichconfiguration the SCell shall use for determining HARQ control timing isbased on a subframe hierarchy, as illustrated in FIG. 11. It should beappreciated that the hierarchical ordering of FIG. 11 is furtherdescribed in WO2013/025143.

The subframe hierarchy may be designed with the following principles:

(1) The UL subframes in a TDD configuration are also UL subframes inthose TDD configurations that can be corrected with upward arrows.

For example, subframes 2 and 3 are UL subframes in configuration 4.These two subframes are also UL in configurations 3, 1, 6 and 0, all ofwhich can be connected from configuration 4 with upward arrows. As asecond example, subframes 2 and 7 are UL subframes in configuration 2.These two subframes are not both UL in configuration 3 because there isno upward arrow connecting the two configurations.

(2) The DL subframes in a TDD configuration are also DL subframes inthose TDD configurations that can be corrected with downward arrows.

For example, subframe 0, 1, 5, 6 and 9 are DL subframes in configuration6. These five subframes are also DL in configurations 1, 2, 3, 4 and 5,all of which can be connected from configuration 6 with downward arrows.As a second example, subframe 7 is a DL subframe in configuration 3 butnot a DL subframe in configuration 2 because there is no downward arrowconnecting the two configurations.

With these design properties, the subframe hierarchy may provide thefollowing utility:

(1) Given a set of TDD configurations to be aggregated, a TDDconfiguration that can be connected from all of the given TDDconfigurations with upward arrows has the following two properties:

-   -   The TDD configuration comprises UL subframes that are a superset        of all UL subframes from all given TDD configurations.    -   The TDD configuration comprises DL subframes that are available        in all given TDD configurations.

Given the subframe hierarchy described above, according to some of theexample embodiments, the PUSCH scheduling and PHICH timings of a FDDSCell shall follow those defined for a UL/DL configuration 0 TDD cell.Alternatively, UL/DL configuration 6 could be used. The advantage ofthis example embodiment is that six (or alternatively five) UL subframeson the FDD SCell may always be scheduled. However, one example drawbackmay be that the PUSCH round trip time for the FDD SCell may becomegreater than 10 ms.

FIG. 12 illustrates an example of FDD SCell scheduling based on thesubframe hierarchy as illustrated in FIG. 11. In FIG. 12, the solidlines indicate PUSCH scheduling timings and the dashed lines indicatePHICH timings. As shown in FIG. 12, the FDD based SCell, which functionsas the scheduled cell, is aggregated with a TDD based PCell with aconfiguration of 1, which functions as the scheduling cell. Asillustrated, the FDD SCell provides HARQ-ACK timing via configuration 0as provided in table 3. Thus, using the n+k calculation, subframes 2, 3,4, 7, 8, and 9 of the FDD based SCell provide HARQ-ACK feedback tosubframes 6, 0, 0, 1, 5 and 5, respectively, of the TDD based PCell.

FIG. 13 illustrates another example of FDD SCell scheduling based on thesubframe hierarchy as illustrated in FIG. 11. In FIG. 13, the solidlines indicate PUSCH scheduling timings and the dashed lines indicatePHICH timings. As shown in FIG. 13, the FDD based SCell, which functionsas the scheduled cell, is aggregated with a TDD based PCell with aconfiguration of 2, which functions as the scheduling cell. Asillustrated, the FDD SCell provides HARQ-ACK timing via configuration 0as provided in table 3. Thus, using the n+k calculation, subframes 2, 3,4, 7, 8, and 9 of the FDD based SCell provide HARQ-ACK feedback tosubframes 6, 0, 0, 1, 5 and 5, respectively, of the TDD based PCell.

FDD SCell Scheduling Based on Revised Tables

According to some of the example embodiments FDD based SCells may bescheduled with the use of revised tables. Such revised tables may beprovided with the use of a combination of the above explainedembodiments.

Thus, according to some of the example embodiments, the PUSCH schedulingand PHICH timings of a FDD SCell shall follow: (1) UL/DL configuration 1as the UL timing reference configuration if the UL/DL configuration ofthe scheduling TDD cell is 2, 4 or 5; and (2) UL/DL configuration of thescheduling cell as the UL timing reference configuration if the UL/DLconfiguration of the scheduling TDD cell is 0, 1, 3 or 6. The powercontrol of the PUSCH transmitted on the scheduled FDD Scell shallincorporate the transmit power control command transmitted within thescheduling DCI according to the above defined UL timing referenceconfiguration.

For a FDD SCell scheduled from a TDD UL/DL configurations 1-6 cell andnormal HARQ operation, the user equipment shall upon detection of aPDCCH/ePDCCH with uplink DCI format and/or a PHICH transmission insubframe n intended for the user equipment, adjust the correspondingPUSCH transmission in subframe n+k, with k given in Table 5.

For a FDD SCell scheduled from a TDD UL/DL configuration 0 cell andnormal HARQ operation, the user equipment shall upon detection of aPDCCH/ePDCCH with uplink DCI format and/or a PHICH transmission insubframe n intended for the user equipment, adjust the correspondingPUSCH transmission in subframe n+k if the MSB of the UL index in thePDCCH/EPDCCH with uplink DCI format is set to 1 or PHICH is received insubframe n=0 or 5 in the resource corresponding to I_(PHICH)=0 with kgiven in Table 5. If the LSB of the UL index in the DCI format 0/4 isset to 1 in subframe n or a PHICH is received in subframe n=0 or 5 inthe resource corresponding to I_(PHICH)=1 or PHICH is received insubframe n=1 or 6, the user equipment shall adjust the correspondingPUSCH transmission in subframe n+7. If both the MSB and LSB of the ULindex in the PDCCH/ePDCCH with uplink DCI format are set in subframe n,the user equipment shall adjust the corresponding PUSCH transmission inboth subframes n+k and n+7, with k given in Table 5.

TABLE 5 Effective k for a FDD Scell scheduled from a TDD cell TDD UL/DLConfiguration of the subframe number n scheduling cell 0 1 2 3 4 5 6 7 89 0 4 6 4 6 1 6 4 6 4 2 6 4 6 4 3 4 4 4 4 6 4 6 4 5 6 4 6 4 6 7 7 7 7 5

For a FDD SCell scheduled from a TDD UL/DL configuration 1-6 cell, anHARQ-ACK received on the PHICH assigned to a user equipment in subframei is associated with the PUSCH transmission in the subframe i-k asindicated by the following Table 6.

For a FDD SCell scheduled from a TDD UL/DL configuration 0 cell, anHARQ-ACK received on the PHICH in the resource corresponding toI_(PHICH)=0, assigned to a user equipment in subframe i is associatedwith the PUSCH transmission in the subframe i-k as indicated by thefollowing Table 6. An HARQ-ACK received on the PHICH in the resourcecorresponding to I_(PHICH)=1 assigned to a user equipment in subframe iis associated with the PUSCH transmission in the subframe i-6.

TABLE 6 Effective k for HARQ-ACK for a FDD Scell received from the PHICHon a TDD scheduling cell TDD UL/DL Configuration of the subframe numberi scheduling cell 0 1 2 3 4 5 6 7 8 9 0 7 4 7 4 1 4 6 4 6 2 4 6 4 6 3 66 6 4 4 6 4 6 5 4 6 4 6 6 6 4 7 4 6

For PUSCH transmissions transmitted on a FDD serving cell and scheduledfrom a TDD serving cell c in subframe n, the user equipment shalldetermine the corresponding PHICH resource of serving cell c in subframen+k_(PHICH), where k_(PHICH) is given in Table 7.

It is further given if there is no PHICH resource available in thedetermined subframe, the user equipment should generate a local HARQ-ACKfor the PHICH transmission. It is further given that a retransmission ofan HARQ process would occur if the user equipment in such a scenariowould receive an UL grant that indicates a retransmission occasion.

TABLE 7 Effective k_(PHICH) for a FDD Scell scheduled from a TDD cellTDD UL/DL Configuration of the subframe index n scheduling cell 0 1 2 34 5 6 7 8 9 0 4 7 6 4 7 6 1 4 6 4 6 2 4 6 4 6 3 6 6 6 4 4 6 4 6 5 4 6 46 6 4 6 6 4 7

Within the downlink control information (DCI) transmitted to the userequipment via PDCCH/EPDCCH for scheduling PUSCH, there is a transmitpower control (TPC) command. For a PUSCH transmission at subframe i on aFDD SCell scheduled from a TDD cell, the TPC command from subframei−K_(PUSCH) should be incorporated, where K_(PUSCH) is given in Table 8.

TABLE 8 Effective K_(PUSCH) for a FDD Scell scheduled from a TDD cellTDD UL/DL Configuration of the subframe number i scheduling cell 0 1 2 34 5 6 7 8 9 0 — — 6 7 4 — — 6 7 4 1 — — 6 4 — — — 6 4 — 2 — — 6 4 — — —6 4 — 3 — — 4 4 4 — — — — — 4 — — 6 4 — — — 6 4 — 5 — — 6 4 — — — 6 4 —6 — — 7 7 5 — — 7 7 —

Cases where the PHICH is Transmitted on the Scheduled FDD Cell

In this setup, the HARQ-ACK for a PUSCH on the scheduled SCell istransmitted on the scheduled cell. According to some of the exampleembodiments, the PUSCH scheduling and PHICH timings of a FDD SCellscheduled from a TDD cell shall follow: (1) UL/DL configuration 0 as theUL timing reference configuration if the UL/DL configuration of thescheduling TDD cell is 0; and (2) FDD PUSCH scheduling and PHICH timingsif the UL/DL configuration of the scheduling TDD cell is 1-6. The powercontrol of the PUSCH transmitted on the scheduled FDD Scell shallincorporate the transmit power control command transmitted within thescheduling DCI according to the FDD serving cell timing.

For a FDD SCell scheduled from a TDD UL/DL configurations 1-6 cell andnormal HARQ operation, the user equipment shall upon detection of aPDCCH/EPDCCH with uplink DCI format and/or a PHICH transmission insubframe n intended for the user equipment, adjust the correspondingPUSCH transmission in subframe n+k, with k given in Table 9.

For a FDD SCell scheduled from a TDD UL/DL configuration 0 cell andnormal HARQ operation, the user equipment shall upon detection of aPDCCH/EPDCCH with uplink DCI format and/or a PHICH transmission insubframe n intended for the user equipment, adjust the correspondingPUSCH transmission in subframe n+k if the MSB of the UL index in thePDCCH/EPDCCH with uplink DCI format is set to 1 or PHICH is received insubframe n=0 or 5 in the resource corresponding to I_(PHICH)=0 with kgiven in Table 9. If the LSB of the UL index in the DCI format 0/4 isset to 1 in subframe n or a PHICH is received in subframe n=0 or 5 inthe resource corresponding to I_(PHICH)=1 or PHICH is received insubframe n=1 or 6, the user equipment shall adjust the correspondingPUSCH transmission in subframe n+7. If both the MSB and LSB of the ULindex in the PDCCH/EPDCCH with uplink DCI format are set in subframe n,the user equipment shall adjust the corresponding PUSCH transmission inboth subframes n+k and n+7, with k given in Table 9.

TABLE 9 Effective k for a FDD Scell scheduled from a TDD cell TDD UL/DLConfiguration of the subframe number n scheduling cell 0 1 2 3 4 5 6 7 89 0 4 6 4 6 1 4 4 4 4 4 4 2 4 4 4 4 4 4 4 4 3 4 4 4 4 4 4 4 4 4 4 4 4 44 4 4 5 4 4 4 4 4 4 4 4 4 6 4 4 4 4 4

For a FDD SCell scheduled from a TDD UL/DL configuration 1-6 cell, anHARQ-ACK received on the PHICH assigned to a UE in subframe i isassociated with the PUSCH transmission in the subframe i-k as indicatedby the following Table 10.

For a FDD SCell scheduled from a TDD UL/DL configuration 0 cell, anHARQ-ACK received on the PHICH in the resource corresponding toI_(PHICH)=0, assigned to a user equipment in subframe i is associatedwith the PUSCH transmission in the subframe i-k as indicated by thefollowing Table 10. An HARQ-ACK received on the PHICH in the resourcecorresponding to I_(PHICH)=1 assigned to a user equipment in subframe iis associated with the PUSCH transmission in the subframe i-6.

TABLE 10 Effective k for HARQ-ACK for a FDD Scell received from thePHICH on a TDD scheduling cell TDD UL/DL Configuration of the subframenumber i scheduling cell 0 1 2 3 4 5 6 7 8 9 0 7 4 7 4 1 4 4 4 4 4 4 2 44 4 4 4 4 4 4 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 4 4 4 4 4 4 4 4 4 6 44 4 4 4

For PUSCH transmissions transmitted on a FDD serving cell and scheduledfrom a TDD serving cell c in subframe n, the user equipment shalldetermine the corresponding PHICH resource of serving cell c in subframen+k_(PHICH), where k_(PHICH) is given in Table 11.

TABLE 11 Effective k_(PHICH) for a FDD SCell scheduled from a TDD cellTDD UL/DL Configuration of the subframe index n scheduling cell 0 1 2 34 5 6 7 8 9 0 4 7 6 4 7 6 1 4 4 4 4 4 4 2 4 4 4 4 4 4 4 4 3 4 4 4 4 4 44 4 4 4 4 4 4 4 4 4 5 4 4 4 4 4 4 4 4 4 6 4 4 4 4 4

Within the downlink control information (DCI) transmitted to the userequipment via PDCCH/EPDCCH for scheduling PUSCH, there is a transmitpower control (TPC) command. For a PUSCH transmission at subframe i on aFDD SCell scheduled from a TDD cell, the TPC command from subframei−K_(PUSCH) should be incorporated, where K_(PUSCH) is given in Table12.

TABLE 12 Effective K_(PUSCH) for a FDD SCell scheduled from a TDD cellTDD UL/DL Configuration of the subframe number i scheduling cell 0 1 2 34 5 6 7 8 9 0 — — 6 7 4 — — 6 7 4 1 4 — — 4 4 4 — — 4 4 2 4 — 4 4 4 4 —4 4 4 3 4 4 4 4 4 4 — — — 4 4 4 4 4 4 4 4 — — 4 4 5 4 4 4 4 4 4 — 4 4 46 4 — — 4 4 4 — — — 4

FIG. 14 is an illustrative example of FDD based SCell scheduling basedon the revised tables presented above. In FIG. 14, the solid linesindicate PUSCH scheduling timings and the dashed lines indicate PHICHtimings. As illustrated in FIG. 14, a FDD based SCell, which functionsas the scheduled cell, is aggregated with a TDD based PCell with aconfiguration number of 1, which functions as the scheduling cell. Inthe example embodiment illustrated in FIG. 14, table 11 is used todetermine the HARQ-ACK feedback timing. Thus, utilizing the n+kcalculation of table 11, subframes 4, 5, 8, 9, 0 and 3 of the FDD basedscheduled cell are scheduled to subframes 8, 9, 2, 3, 4 and 7,respectively, of the FDD based scheduled cell.

FIG. 15 is an illustrative another example of FDD based SCell schedulingbased on the revised tables presented above. In FIG. 15, the solid linesindicate PUSCH scheduling timings and the dashed lines indicate PHICHtimings. As illustrated in FIG. 15, a FDD based SCell, which functionsas the scheduled cell, is aggregated with a TDD based PCell with aconfiguration number of 2, which functions as the scheduling cell. Inthe example embodiment presented in FIG. 15, table 11 is used todetermine the HARQ-ACK feedback timing. Thus, utilizing the n+kcalculation of table 11, subframes 4, 5, 7, 8, 9, 0, 1 and 2 of the FDDbased scheduled cell are scheduled to subframes 8, 9, 1, 2, 3, 4, 5 and6, respectively, of the FDD based scheduled cell.

Example Node Configurations

FIG. 16 illustrates an example node configuration of a base station 401which may perform some of the example embodiments described herein. Thebase station 401 may comprise radio circuitry or a communication port410 that may be configured to receive and/or transmit communicationdata, instructions, and/or messages. It should be appreciated that theradio circuitry or communication port 410 may comprise any number oftransceiving, receiving, and/or transmitting units or circuitry. Itshould further be appreciated that the radio circuitry or communicationport 410 may be in the form of any input or output communications portknown in the art. The radio circuitry or communication port 410 maycomprise RF circuitry and baseband processing circuitry (not shown).

The base station 401 may also comprise a processing unit or circuitry420 which may be configured to implement HARQ-ACK control timing asdescribed herein. The processing circuitry 420 may be any suitable typeof computation unit, for example, a microprocessor, digital signalprocessor (DSP), field programmable gate array (FPGA), or applicationspecific integrated circuit (ASIC), or any other form of circuitry. Thebase station 401 may further comprise a memory unit or circuitry 430which may be any suitable type of computer readable memory and may be ofvolatile and/or non-volatile type. The memory 430 may be configured tostore received, transmitted, and/or measured data, device parameters,communication priorities, and/or executable program instructions, e.g.,scheduling instructions. The memory 430 may also be configured to storeany form of configuration tables as described herein.

FIG. 17 illustrates an example node configuration of a user equipment501 which may perform some of the example embodiments described herein.The user equipment 501 may comprise radio circuitry or a communicationport 510 that may be configured to receive and/or transmit communicationdata, instructions, and/or messages. It should be appreciated that theradio circuitry or communication port 510 may comprise any number oftransceiving, receiving, and/or transmitting units or circuitry. Itshould further be appreciated that the radio circuitry or communicationport 510 may be in the form of any input or output communications portknown in the art. The radio circuitry or communication port 510 maycomprise RF circuitry and baseband processing circuitry (not shown).

The user equipment 501 may also comprise a processing unit or circuitry520 which may be configured to implement HARQ-ACK control timing, asdescribed herein. The processing circuitry 520 may be any suitable typeof computation unit, for example, a microprocessor, digital signalprocessor (DSP), field programmable gate array (FPGA), or applicationspecific integrated circuit (ASIC), or any other form of circuitry. Theuser equipment 501 may further comprise a memory unit or circuitry 530which may be any suitable type of computer readable memory and may be ofvolatile and/or non-volatile type. The memory 530 may be configured tostore received, transmitted, and/or measured data, device parameters,communication priorities, and/or executable program instructions, e.g.,scheduling instructions. The memory 530 may also be configured to storeany form of configuration tables as described herein.

Example Node Operations

FIG. 18 is a flow diagram depicting example operations which may beperformed by the base station 401 as described herein to implementHARQ-ACK control timing, as described herein. It should be appreciatedthat FIG. 18 comprises some operations which are illustrated with asolid border and some operations which are illustrated with a dashedborder. The operations which are comprised in a solid border areoperations which are comprised in the broadest example embodiment. Theoperations which are comprised in a dashed border are exampleembodiments which may be comprised in, or a part of, or are furtheroperations which may be performed in addition to the operations of thebroader example embodiments. It should be appreciated that theseoperations need not be performed in order. Furthermore, it should beappreciated that not all of the operations need to be performed. Theexample operations may be performed in any order and in any combination.

The example operations of FIG. 18 describe a base station, andcorresponding method, for determining a control timing configuration.The control timing configuration provides a subframe timing setting forconfiguration PUSCH and uplink HARQ-ACK control timing for a cellserving a user equipment in a multiple cell communications network. Theuser equipment is served by a TDD based cell and a FDD based cell.

Operation 10

The base station 401 is configured to determine a control timingconfiguration for a secondary cell. The secondary cell is one of the TDDbased cell or the FDD based cell. The determination of the controltiming configuration is based on a type of the scheduling cell. The typeof the scheduling cell is either FDD or TDD. The processing circuitry420 is configured to determine the control timing configuration for thesecondary cell.

Example Operation 12

According to some of the example embodiments, the determining 10 mayfurther comprise determining 12 the control timing configuration tocomprise a transmission timing value of 4 for all subframes for a PUSCH,where downlink subframes of the scheduling cell which map to downlinksubframes of the secondary cell are excluded from PUSCH timing. Theprocessing circuitry 420 is configured to determine the control timingconfiguration to comprise a transmission timing value of 4 for allsubframes for a PUSCH, where downlink subframes of the scheduling cellwhich map to downlink subframes of the secondary cell are excluded fromPUSCH timing.

According to some of the example embodiments, in example operation 12,the secondary cell may be either the FDD based cell or the TDD basedcell. Furthermore, the scheduling cell may be the TDD based cell or theFDD based cell.

An example of operation 12 is provided under at least the heading “TheFDD based cell as the scheduling cell” and subheading “Scheduled SCellfollows FDD timing”, as well as FIG. 5. As shown in FIG. 5, the TDDbased SCell follows FDD timing, specifically, a timing value of 4 isutilized for all subframes for a PUSCH.

A further example of operation 12 is provided under the heading “The TDDbased cell as the scheduling cell” and subheading “Scheduled SCellfollows FDD timing”, as well as FIGS. 9 and 10. As illustrated in FIGS.9 and 10, the FDD based SCell follows its own timing, specifically, atiming value of 4 is utilized for all subframes for a PUSCH.

Example Operation 14

According to some of the example embodiments, the determining 10 mayfurther comprise determining 14 the control timing configuration to beequivalent to a TDD configuration of the TDD based cell. The processingcircuitry 420 is configured to determine the control timingconfiguration to be equivalent to a TDD configuration of the TDD basedcell.

According to some of the example embodiments, in example operation 14,the secondary cell may be either the FDD based cell or the TDD basedcell. Furthermore, the scheduling cell may be the TDD based cell or theFDD based cell.

An example of operation 14 is provided under at least the heading “TheFDD based cell as the scheduling cell” and subheading “Scheduled SCellfollows TDD timing”, as well as FIG. 6. As illustrated in FIG. 6, a TDDbased SCell follows its own configuration. Thus, in the example providedin FIG. 6, the TDD based SCell follows control timing according toconfiguration 1, which is the configuration of the TDD based SCell.

A further example of operation 14 is provided under at least the heading“The TDD based cell as the scheduling cell” and subheading “ScheduledSCell follows TDD timing”, as well as FIGS. 7 and 8. As shown in FIG. 7,the FDD based SCell follows the control timing according to theconfiguration of the TDD based PCell, which functions as the schedulingcell. Specifically, the FDD based SCell follows the control timingaccording to configuration 1, which is the configuration of the TDDbased PCell. Similarly, in FIG. 8, the FDD based SCell follows controltiming according to configuration 2, which is the configuration of thescheduling TDD based PCell.

Example Operation 16

According to some of the example embodiments, the secondary cell is theFDD based cell and the scheduling cell is the TDD based cell. Accordingto such example embodiments, the determining 10 further comprisesdetermining 16 the control timing configuration to be equivalent to aconfiguration number of 0 or 6. The processing circuitry 420 isconfigured to determine the control timing configuration to beequivalent to a configuration number of 0 or 6.

Example operation 16 is further described under at least the heading“The TDD based cell as the scheduling cell” and the subheading“Scheduled SCell follows timing according to subframe hierarchy” andFIGS. 12 and 13. According to some of the example embodiments,scheduling based on a subframe hierarchy provides that either aconfiguration of 0 or 6 is chosen for scheduling the FDD based SCell. Itshould be appreciated that the choice of a configuration number of 0 or6 is provided with respect to a subframe hierarchy as explained in FIG.11.

As shown in FIG. 12, a FDD based SCell, functioning as the scheduledcell, is aggregated with a TDD based PCell with a configuration of 1,functioning as the scheduling cell. In the example provided in FIG. 12,the FDD based SCell is scheduled with a configuration of 0 as providedby the subframe hierarchy of FIG. 11.

FIG. 13 illustrates a FDD based SCell, functioning as the scheduledcell, is aggregated with a TDD based PCell with a configuration of 2,functioning as the scheduling cell. In the example provided in FIG. 13,the FDD based SCell is scheduled with a configuration of 0 as providedby the subframe hierarchy of FIG. 11.

Example Operation 18

According to some of the example embodiments, the scheduling cell is theTDD based cell and the secondary cell is the FDD based cell. Accordingto such example embodiments, the determining 10 may further comprisedetermining 18 the control timing configuration to be configurationnumber 1 if a configuration number of the scheduling cell is 2, 4 or 5.The processing circuitry 420 is configure to determine the controltiming configuration to be configuration number 1 if a configurationnumber of the scheduling cell is 2, 4 or 5.

Example operation 18 is further described under at least the heading“The TDD based cell as the scheduling cell” and subheading “FDD SCellscheduling based on revised tables” as well as tables 5-8. Asillustrated in tables 5-8, for configurations 2, 4 and 5, the k valuesof configuration 1 have been provided from tables 1-4, respectively. Allother configurations of tables 5-8 comprise the normal configurations asprovided in tables 1-4, respectively. Thus, tables 5-8 are revisedtables.

Example Operation 20

According to some of the example embodiments, the operation ofdetermining 10 and the example operation of determining 18 may furthercomprise, if the configuration number of the scheduling cell is not 2, 4or 5, determining 20 the control timing configuration to be equivalentto the configuration number of the scheduling cell. The processingcircuitry 420 is configured to determine the control timingconfiguration to be equivalent to the configuration number of thescheduling cell.

Example operation 20 is further described under at least the heading“The TDD based cell as the scheduling cell” and subheading “FDD SCellscheduling based on revised tables” as well as tables 5-8. Asillustrated in tables 5-8, for configurations 2, 4 and 5, the k valuesof configuration 1 have been provided from tables 1-4, respectively. Allother configurations of tables 5-8 comprise the normal configurations asprovided in tables 1-4, respectively. Thus, tables 5-8 are revisedtables.

Example Operation 22

According to some of the example embodiments the scheduling cell is theTDD based cell and the secondary cell is the FDD based cell. Accordingto such example embodiments, the HARQ-ACK is transmitted on thesecondary cell. Accordingly, the determining 10 may further comprisedetermining 22 the control timing configuration to be configurationnumber 0 if the configuration of the scheduling cell is 0. Theprocessing circuitry 420 is configured determine the control timingconfiguration to be configuration number 0 if the configuration of thescheduling cell is 0.

Example operation 22 is further described under at least the heading“The TDD based cell as the scheduling cell” and subheading “Cases wherethe PHICH is transmitted on the scheduled FDD cell” as well as tables9-12. As illustrated in tables 9-12, for configuration 0, the k valuesof configuration 0 have been provided from tables 1-4, respectively. Allother configurations of tables 9-12 comprise FDD timing values,specifically a timing value of 4 for all subframes for a PUSCH. Itshould be appreciated that the tables for configurations 1-6 areconstructed in order to exclude downlink subframes of the FDD based cellto map to uplink subframes of the TDD based PCell (e.g., the schedulingcell). Thus, tables 9-12 are revised tables.

Example Operation 24

According to some of the example embodiments, the operation ofdetermining 10 and the example operation of determining 22 furthercomprise, if the configuration number of the scheduling cell is not 0,determining 24 the control timing configuration to be a HARQ-ACKfeedback timing value of 4 for a subframe in which a corresponding TDDsubframe, for a same configuration number, is a downlink subframe. Theprocessing circuitry 420 is configured to determine the control timingconfiguration to be a HARQ-ACK feedback timing value of 4 for a subframein which a corresponding TDD subframe, for a same configuration number,is a downlink subframe.

Example operation 24 is further described under at least the heading“The TDD based cell as the scheduling cell” and subheading “Cases wherethe PHICH is transmitted on the scheduled FDD cell” as well as tables9-12. As illustrated in tables 9-12, for configuration 0, the k valuesof configuration 0 have been provided from tables 1-4, respectively. Allother configurations of tables 9-12 comprise FDD timing values,specifically a timing value of 4 for all subframes for a PUSCH. Itshould be appreciated that the tables for configurations 1-6 areconstructed in order to exclude downlink subframes of the FDD based cellto map to uplink subframes of the TDD based PCell (e.g., the schedulingcell). Thus, tables 9-12 are revised tables.

Operation 26

The base station is further configured to implement the control timingconfiguration for PUSCH and uplink HARQ-ACK control timing for a cellserving the user equipment. The processing circuitry 420 is configuredto implement the control timing configuration for PUSCH and uplinkHARQ-ACK control timing for a cell serving the user equipment.

Example Operation 28

According to some of the example embodiments, the base station may befurther configured to send, to the user equipment, the implementedcontrol timing configuration via RRC signalling. The radio circuitry 410is configured to send, to the user equipment, the implement controltiming configuration via RRC signalling.

FIG. 19 is a flow diagram depicting example operations which may beperformed by the user equipment 501 as described herein to implementHARQ-ACK control timing, as described herein. It should be appreciatedthat FIG. 19 comprises some operations which are illustrated with asolid border and some operations which are illustrated with a dashedborder. The operations which are comprised in a solid border areoperations which are comprised in the broadest example embodiment. Theoperations which are comprised in a dashed border are exampleembodiments which may be comprised in, or a part of, or are furtheroperations which may be performed in addition to the operations of thebroader example embodiments. It should be appreciated that theseoperations need not be performed in order. Furthermore, it should beappreciated that not all of the operations need to be performed. Theexample operations may be performed in any order and in any combination.

The example operations of FIG. 19 describe a user equipment, andcorresponding method, for determining a control timing configuration.The control timing configuration provides a subframe timing setting forconfiguration PUSCH and uplink HARQ-ACK control timing for a cellserving a user equipment in a multiple cell communications network. Theuser equipment is served by a TDD based cell and a FDD based cell.

Operation 30

The user equipment 501 is configured to determine a control timingconfiguration for a secondary cell. The secondary cell is one of the TDDbased cell or the FDD based cell. The determination of the controltiming configuration is based on a type of the scheduling cell. The typeof the scheduling cell is either FDD or TDD. The processing circuitry520 is configured to determine the control timing configuration for thesecondary cell.

Example Operation 32

According to some of the example embodiments, the determining 30 mayfurther comprise determining 32 the control timing configuration tocomprise a transmission timing value of 4 for all subframes for a PUSCH,where downlink subframes of the scheduling cell which map to downlinksubframes of the secondary cell are excluded form PUSCH timing. Theprocessing circuitry 520 is configured to determine the control timingconfiguration to comprise a transmission timing value of 4 for allsubframes for a PUSCH, where downlink subframes of the scheduling cellwhich map to downlink subframes of the secondary cell are excluded fromPUSCH timing.

According to some of the example embodiments, according to exampleoperation 32, the secondary cell may be either the FDD based cell or theTDD based cell. Furthermore, the scheduling cell may be the TDD basedcell or the FDD based cell.

An example of operation 32 is provided under at least the heading “TheFDD based cell as the scheduling cell” and subheading “Scheduled SCellfollows FDD timing”, as well as FIG. 5. As shown in FIG. 5, the TDDbased SCell follows FDD timing, specifically, a timing value of 4 isutilized for all subframes for a PUSCH.

A further example of operation 32 is provided under the heading “The TDDbased cell as the scheduling cell” and subheading “Scheduled SCellfollows FDD timing”, as well as FIGS. 9 and 10. As illustrated in FIGS.9 and 10, the FDD based SCell follows its own timing, specifically, atiming value of 4 is utilized for all subframes for a PUSCH.

Example Operation 34

According to some of the example embodiments, the determining 30 mayfurther comprise determining 34 the control timing configuration to beequivalent to a TDD configuration of the TDD based cell. The processingcircuitry 520 is configured to determine the control timingconfiguration to be equivalent to a TDD configuration of the TDD basedcell.

According to some of the example embodiments, according to exampleoperation 34, the secondary cell may be either the FDD based cell or theTDD based cell. Furthermore, the scheduling cell may be the TDD basedcell or the FDD based cell.

An example of operation 34 is provided under at least the heading “TheFDD based cell as the scheduling cell” and subheading “Scheduled SCellfollows TDD timing”, as well as FIG. 6. As illustrated in FIG. 6, a TDDbased SCell follows its own configuration. Thus, in the example providedin FIG. 6, the TDD based SCell follows control timing according toconfiguration 1, which is the configuration of the TDD based SCell.

A further example of operation 34 is provided under at least the heading“The TDD based cell as the scheduling cell” and subheading “ScheduledSCell follows TDD timing”, as well as FIGS. 7 and 8. As shown in FIG. 7,the FDD based SCell follows the control timing according to theconfiguration of the TDD based PCell, which functions as the schedulingcell. Specifically, the FDD based SCell follows the control timingaccording to configuration 1, which is the configuration of the TDDbased PCell. Similarly, in FIG. 8, the FDD based SCell follows controltiming according to configuration 2, which is the configuration of thescheduling TDD based PCell.

Example Operation 36

According to some of the example embodiments, the secondary cell is theFDD based cell and the scheduling cell is the TDD based cell. Accordingto such example embodiments, the determining 30 further comprisesdetermining 36 the control timing configuration to be equivalent to aconfiguration number of 0 or 6. The processing circuitry 520 isconfigured to determine the control timing configuration to beequivalent to a configuration number of 0 or 6.

Example operation 36 is further described under at least the heading“The TDD based cell as the scheduling cell” and the subheading“Scheduled SCell follows timing according to subframe hierarchy” andFIGS. 12 and 13. According to some of the example embodiments,scheduling based on a subframe hierarchy provides that either aconfiguration of 0 or 6 is chosen for scheduling the FDD based SCell. Itshould be appreciated that the choice of a configuration number of 0 or6 is provided with respect to a subframe hierarchy as explained in FIG.11.

As shown in FIG. 12, a FDD based SCell, functioning as the scheduledcell, is aggregated with a TDD based PCell with a configuration of 1,functioning as the scheduling cell. In the example provided in FIG. 12,the FDD based SCell is scheduled with a configuration of 0 as providedby the subframe hierarchy of FIG. 11.

FIG. 13 illustrates a FDD based SCell, functioning as the scheduledcell, is aggregated with a TDD based PCell with a configuration of 2,functioning as the scheduling cell. In the example provided in FIG. 13,the FDD based SCell is scheduled with a configuration of 0 as providedby the subframe hierarchy of FIG. 11.

Example Operation 38

According to some of the example embodiments, the scheduling cell is theTDD based cell and the secondary cell is the FDD based cell. Accordingto such example embodiments, the determining 30 may further comprisedetermining 38 the control timing configuration to be configurationnumber 1 if a configuration number of the scheduling cell is 2, 4 or 5.The processing circuitry 520 is configured to determine the controltiming configuration to be configuration number 1 if a configurationnumber of the scheduling cell is 2, 4 or 5.

Example operation 38 is further described under at least the heading“The TDD based cell as the scheduling cell” and subheading “FDD SCellscheduling based on revised tables” as well as tables 5-8. Asillustrated in tables 5-8, for configurations 2, 4 and 5, the k valuesof configuration 1 have been provided from tables 1-4, respectively. Allother configurations of tables 5-8 comprise the normal configurations asprovided in tables 1-4, respectively. Thus, tables 5-8 are revisedtables.

Example Operation 40

According to some of the example embodiments, the operation ofdetermining 30 and the example operation of determining 38 may furthercomprise, if the configuration number of the scheduling cell is not 2, 4or 5, determining 40 the control timing configuration to be equivalentto the configuration number of the scheduling cell. The processingcircuitry 520 is configured to determine the control timingconfiguration to be equivalent to the configuration number of thescheduling cell.

Example operation 40 is further described under at least the heading“The TDD based cell as the scheduling cell” and subheading “FDD SCellscheduling based on revised tables” as well as tables 5-8. Asillustrated in tables 5-8, for configurations 2, 4 and 5, the k valuesof configuration 1 have been provided from tables 1-4, respectively. Allother configurations of tables 5-8 comprise the normal configurations asprovided in tables 1-4, respectively. Thus, tables 5-8 are revisedtables.

Example Operation 42

According to some of the example embodiments the scheduling cell is theTDD based cell and the secondary cell is the FDD based cell. Accordingto such example embodiments, the HARQ-ACK is transmitted on thesecondary cell. Accordingly, the determining 30 may further comprisedetermining 42 the control timing configuration to be configurationnumber 0 if the configuration of the scheduling cell is 0. Theprocessing circuitry 520 is configured determine the control timingconfiguration to be configuration number 0 if the configuration of thescheduling cell is 0.

Example operation 42 is further described under at least the heading“The TDD based cell as the scheduling cell” and subheading “Cases wherethe PHICH is transmitted on the scheduled FDD cell” as well as tables9-12. As illustrated in tables 9-12, for configuration 0, the k valuesof configuration 0 have been provided from tables 1-4, respectively. Allother configurations of tables 9-12 comprise FDD timing values,specifically a timing value of 4 for all subframes for a PUSCH. Itshould be appreciated that the tables for configurations 1-6 areconstructed in order to exclude downlink subframes of the FDD based cellto map to uplink subframes of the TDD based PCell (e.g., the schedulingcell). Thus, tables 9-12 are revised tables.

Example Operation 44

According to some of the example embodiments, the operation ofdetermining 30 and the example operation of determining 42 furthercomprise, if the configuration number of the scheduling cell is not 0,determining 44 the control timing configuration to be a HARQ-ACKfeedback timing value of 4 for a subframe in which a corresponding TDDsubframe, for a same configuration number, is a downlink subframe. Theprocessing circuitry 520 is configured to determine the control timingconfiguration to be a HARQ-ACK feedback timing value of 4 for a subframein which a corresponding TDD subframe, for a same configuration number,is a downlink subframe.

Example operation 44 is further described under at least the heading“The TDD based cell as the scheduling cell” and subheading “Cases wherethe PHICH is transmitted on the scheduled FDD cell” as well as tables9-12. As illustrated in tables 9-12, for configuration 0, the k valuesof configuration 0 have been provided from tables 1-4, respectively. Allother configurations of tables 9-12 comprise FDD timing values,specifically a timing value of 4 for all subframes for a PUSCH. Itshould be appreciated that the tables for configurations 1-6 areconstructed in order to exclude downlink subframes of the FDD based cellto map to uplink subframes of the TDD based PCell (e.g., the schedulingcell). Thus, tables 9-12 are revised tables.

Example Operation 46

According to some of the example embodiments, the determining 30 mayfurther comprise receiving, from the base station, the control timingconfiguration via RRC signalling. The radio circuitry 510 is configuredto receive, from the base station, the control timing configuration viaRRC signalling.

Operation 48

The user equipment is further configured to implement 48 the controltiming configuration for PUSCH and uplink HARQ-ACK control timing for acell serving the user equipment. The processing circuitry 520 isconfigured to implement the control timing configuration for PUSCH anduplink HARQ-ACK control timing for a cell serving the user equipment.

It should be noted that although terminology from 3GPP LTE has been usedherein to explain the example embodiments, this should not be seen aslimiting the scope of the example embodiments to only the aforementionedsystem. Other wireless systems, comprising HSPA, WCDMA, WiMax, UMB, WiFiand GSM, may also benefit from the example embodiments disclosed herein.

The description of the example embodiments provided herein have beenpresented for purposes of illustration. The description is not intendedto be exhaustive or to limit example embodiments to the precise formdisclosed, and modifications and variations are possible in light of theabove teachings or may be acquired from practice of various alternativesto the provided embodiments. The examples discussed herein were chosenand described in order to explain the principles and the nature ofvarious example embodiments and its practical application to enable oneskilled in the art to utilize the example embodiments in various mannersand with various modifications as are suited to the particular usecontemplated. The features of the embodiments described herein may becombined in all possible combinations of methods, apparatuses, modules,systems, and computer program products. It should be appreciated thatthe example embodiments presented herein may be practiced in anycombination with each other.

It should be noted that the word “comprising” does not necessarilyexclude the presence of other elements or steps than those listed andthe words “a” or “an” preceding an element do not exclude the presenceof a plurality of such elements. It should further be noted that anyreference signs do not limit the scope of the claims, that the exampleembodiments may be implemented at least in part by means of bothhardware and software, and that several “means”, “units” or “devices”may be represented by the same item of hardware.

Also note that terminology such as user equipment should be consideredas non-limiting. A wireless terminal or user equipment (UE) as the termis used herein, is to be broadly interpreted to comprise aradiotelephone having ability for Internet/intranet access, web browser,organizer, calendar, a camera, e.g., video and/or still image camera, asound recorder, e.g., a microphone, and/or global positioning system(GPS) receiver; a personal communications system (PCS) user equipmentthat may combine a cellular radiotelephone with data processing; apersonal digital assistant (PDA) that can comprise a radiotelephone orwireless communication system; a laptop; a camera, e.g., video and/orstill image camera, having communication ability; and any othercomputation or communication device capable of transceiving, such as apersonal computer, a home entertainment system, a television, etc. Itshould be appreciated that the term user equipment may also comprise anynumber of connected devices, wireless terminals or machine-to-machinedevices.

It should further be appreciated that the term dual connectivity shouldnot be limited to a user equipment or wireless terminal being connectedto only two base stations. In dual connectivity a wireless terminal maybe connected to any number of base stations.

The various example embodiments described herein are described in thegeneral context of method steps or processes, which may be implementedin one aspect by a computer program product, embodied in acomputer-readable medium, comprising computer-executable instructions,such as program code, executed by computers in networked environments. Acomputer-readable medium may comprise removable and non-removablestorage devices comprising, but not limited to, Read Only Memory (ROM),Random Access Memory (RAM), compact discs (CDs), digital versatile discs(DVD), etc. Generally, program modules may comprise routines, programs,objects, components, data structures, etc. that perform particular tasksor implement particular abstract data types. Computer-executableinstructions, associated data structures, and program modules representexamples of program code for executing steps of the methods disclosedherein. The particular sequence of such executable instructions orassociated data structures represents examples of corresponding acts forimplementing the functions described in such steps or processes.

In the drawings and specification, there have been disclosed exemplaryembodiments. However, many variations and modifications can be made tothese embodiments. Accordingly, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation.

What is claimed is:
 1. A method, in a base station, for determining acontrol timing configuration, the control timing configuration providinga subframe timing setting for configuring Physical Uplink SharedChannel, PUSCH, and uplink Hybrid Automatic Retransmission RequestAcknowledgment, HARQ-ACK, control timing for a cell serving a userequipment in a multiple cell communications network, the user equipmentbeing served by a Time Division Duplex, TDD, based cell, and a FrequencyDivision Duplex, FDD, based cell, the method comprising: determining acontrol timing configuration for a secondary cell, the secondary cellbeing one of the TDD based cell or the FDD based cell, based on a typeof a scheduling cell, the type of the scheduling cell being one of theFDD based cell or the TDD based cell; implementing the control timingconfiguration for PUSCH and uplink HARQ-ACK control timing for a cellserving the user equipment; and if the cell serving the user equipmentis a FDD based cell, the determining further comprising determining thecontrol timing configuration for the PUSCH follows FDD timing.
 2. Themethod of claim 1, further comprising determining the control timingconfiguration comprises a transmission timing value of 4 for allsubframes for a Physical Uplink Shared Channel, PUSCH.
 3. The method ofclaim 1, wherein the scheduling cell is the TDD based cell and thesecondary cell is the FDD based cell, and wherein HARQ-ACK istransmitted on the secondary cell, the determining further comprising:determining the control timing configuration to be configuration number0 if a configuration number of the scheduling cell is 0; and if theconfiguration number of the scheduling cell is not 0, determining thecontrol timing configuration to be a HARQ-ACK feedback timing value of 4for a subframe in which a corresponding TDD subframe, for a sameconfiguration number, is a downlink subframe.
 4. A base station fordetermining a control timing configuration, the control timingconfiguration providing a subframe timing setting for configuringPhysical Uplink Shared Channel, PUSCH, and uplink Hybrid AutomaticRetransmission Request Acknowledgment, HARQ-ACK, control timing for acell serving a user equipment in a multiple cell communications network,the user equipment being served by a Time Division Duplex, TDD, basedcell, and a Frequency Division Duplex, FDD, based cell, the base stationcomprising: processing circuitry configured to: determine a controltiming configuration for a secondary cell, the secondary cell being oneof TDD based cell or the FDD based cell, based on a type of a schedulingcell, the scheduling cell being one of the FDD based cell or the TDDbased cell; and said processing circuitry further configured toimplement the control timing configuration for PUSCH and uplink HARQ-ACKcontrol timing for a cell serving the user equipment; and if the cellserving the user equipment is a FDD based cell, the control timingconfiguration for the PUSCH follows FDD timing.
 5. The base station ofclaim 4, wherein the processing circuitry further configured todetermine the control timing configuration comprises a transmissiontiming value of 4 for all subframes for a Physical Uplink SharedChannel, PUSCH, wherein downlink subframes of the scheduling cell whichmap to downlink subframes of the secondary cell are excluded from PUSCHtiming.
 6. The base station of claim 4, wherein the scheduling cell isthe TDD based cell and the secondary cell is the FDD based cell, andwherein HARQ-ACK is transmitted on the secondary cell, the processingcircuitry is further configured to determine the control timingconfiguration to be configuration number 0 if a configuration number ofthe scheduling cell is 0; and if the configuration number of thescheduling cell is not 0, the processing circuitry is further configuredto determine the control timing configuration to be a HARQ-ACK feedbacktiming value of 4 for a subframe in which a corresponding TDD subframe,for a same configuration number, is a downlink subframe.
 7. A method, ina user equipment, for determining a control timing configuration, thecontrol timing configuration providing a subframe timing setting forconfiguring Physical Uplink Shared Channel, PUSCH, and uplink HybridAutomatic Retransmission Request Acknowledgment, HARQ-ACK, controltiming for a cell serving the user equipment in a multiple cellcommunications network, the user equipment being served by a TimeDivision Duplex, TDD, based cell, and a Frequency Division Duplex, FDD,based cell, the method comprising: determining a control timingconfiguration for a secondary cell, the secondary cell being one of theTDD based cell or the FDD based cell, based on a type of a schedulingcell, the type of the scheduling cell being one of the FDD based cell orthe TDD based cell; and implementing the control timing configurationfor PUSCH and uplink HARQ-ACK control timing for a cell serving the userequipment; and if the cell serving the user equipment is a FDD basedcell, the determining further comprising determining the control timingconfiguration for the PUSCH follows FDD timing.
 8. The method of claim7, wherein the control timing configuration comprises a transmissiontiming value of 4 for all subframes for a Physical Uplink SharedChannel, PUSCH.
 9. The method of claim 8, wherein the scheduling cell isthe TDD based cell and the secondary cell is the FDD based cell, andwherein HARQ-ACK is transmitted on the secondary cell, the determiningfurther comprising: determining the control timing configuration to beconfiguration number 0 if a configuration number of the scheduling cellis 0; and if the configuration number of the scheduling cell is not 0,determining the control timing configuration to be a HARQ-ACK feedbacktiming value of 4 for a subframe in which a corresponding TDD subframe,for a same configuration number, is a downlink subframe.
 10. A userequipment for determining a control timing configuration, the controltiming configuration providing a subframe timing setting for configuringPhysical Uplink Shared Channel, PUSCH, and uplink Hybrid AutomaticRetransmission Request Acknowledgment, HARQ-ACK, control timing for acell serving the user equipment in a multiple cell communicationsnetwork, the user equipment being served by a Time Division Duplex, TDD,based cell, and a Frequency Division Duplex, FDD, based cell, the userequipment comprising: processing circuitry configured to: determine thecontrol timing configuration for a secondary cell, the secondary cellbeing one of the TDD based cell or the FDD based cell, based on a typeof a scheduling cell, the type of the scheduling cell being one of theFDD based cell or the TDD based cell; and the processing circuitryfurther configured to implement the control timing configuration forPUSCH and uplink HARQ-ACK control timing for a cell serving the userequipment; and, if the cell serving the user equipment is a FDD basedcell, the determining further comprising determining the control timingconfiguration for the PUSCH follows FDD timing.
 11. The user equipmentof claim 10, further configured to determine the control timingconfiguration comprises a transmission timing value of 4 for allsubframes for a Physical Uplink Shared Channel, PUSCH.
 12. The userequipment of claim 10, wherein the scheduling cell is the TDD based celland the secondary cell is the FDD based cell, and wherein HARQ-ACK istransmitted on the secondary cell, the processing circuitry is furtherconfigured to determine the control timing configuration to beconfiguration number 0 if a configuration number of the scheduling cellis 0; and if the configuration number of the scheduling cell is not 0,the processing circuitry is further configured to determine the controltiming configuration to be a HARQ-ACK feedback timing value of 4 for asubframe in which a corresponding TDD subframe, for a same configurationnumber, is a downlink subframe.